The front and rear ends of a backhoe loader are a loading end and a digging end respectively, such that one and the same machine can implement loading and digging functions, and therefore, a backhoe loader is commonly known as “backhoe loader”.
The current backhoe loader generally employs a forward eight-bar linkage or forward six-bar linkage mechanism in order to enhance the lifting performance of the loading end, and taking the lifting balance of the loading end into overall account, the forward eight-bar linkage structure would be chosen by most of manufacturers. In general, a forward eight-bar linkage structure has eleven hinge points; and a rotatable bucket oil cylinder, a rotatable bucket lever and a rotatable bucket pull link are hinged at one and the same point together, but such working device where the three bars are hinged at one and the same point has a relatively small breakout force in the case of equal engine power. The dimension, scale and the hinge point position of each bar of a working device of the forward eight-bar linkage structure are different from one another, thus resulting in different dumping height, dumping distance and breakout force.